Beschreibung

Returns a connection identifier needed for most other OCI8 operations.

See Connection Handling for
general information on connection management and connection
pooling.

From PHP 5.1.2 (PECL OCI8 1.1) oci_close() can
be used to close the connection.

The second and subsequent calls to oci_connect()
with the same parameters will return the connection handle returned
from the first call. This means that transactions in one handle are
also in the other handles, because they use the
same underlying database connection. If two
handles need to be transactionally isolated from each other, use
oci_new_connect() instead.

When using the OCI_CRED_EXT in php if the ENV $ORACLE_SID is set the DB does not need to be specified explicitly and the connection will fail unless you provide a NULL DB value when creating the connection.

The $ORACLE_SID trumps the TNS name look up for the connection. So even a manual connection string in the DB parameter will fail.

So when the $ORACLE_SID Env is set a NULL passed instead of the DB name connects successfully.

Hope this saves some hair pulling when moving to %.3 and OS Authentications

If you want to specify a connection timeout in case there is network problem, you can edit the client side (e.g. PHP side) sqlnet.ora file and set SQLNET.OUTBOUND_CONNECT_TIMEOUT. This sets the upper time limit for establishing a connection right through to the DB, including the time for attempts to connect to other services. It is available from Oracle 10.2.0.3 onwards.

In Oracle 11.1, a slightly lighter-weight solution TCP.CONNECT_TIMEOUT was introduced. It also is a sqlnet.ora parameter. It bounds just the TCP connection establishment time, which is mostly where connection problem are seen.

The client sqlnet.ora file should be put in the same directory as the tnsnames.ora file.

For a quick and dirty ldap tnsnames server use tnsManager by Dave Berry. Oracle OID or Openldap can used, but are complicated to setup. tnsManager is a no brainer. The quick part: give it a tnsnames.ora file and start it up. The dirty parts: I can't get Toad and SQLDeveloper to work with it, it ignores the domain and it is no longer being maintained.

The order of values in NAMES.DIRECTORY_PATH in sqlnet.ora determines which look up 'adapter' is used, in this case it is tnsnames.ora file and then ldap. I use ldap for general consumption and tnsnames.ora file to override ldap or entries that are not for general consumption.

If you have the full Oracle client you have tnsping. 'tnsping ORACLE_SID' will tell you what adapter you are using: 'Used LDAP adapter to resolve the alias'.

ISSUE: If connecting with only ORACLE_SID and not ORACLE_SID.DB_DOMAIN, the value of NAMES.DEFAULT_DOMAIN from sqlnet.ora is appended, then for some reason PHP tries the HOSTNAME adapter, and if the database name resolves in DNS, it will fail connecting using the database name as the hostname, because neither SID nor SERVICE_NAME are defined. If using tnsManager append '.ANY_DOMAIN' to $ORACLE_SID to hack around the issue above.

I have tested with: 11.1.0.7 full client and PHP 5.1.6 11.2.0.2 full client and PHP 5.4.11

I have heard that LDAP lookup does not work with older instantclients.

There is a useful solution to the problem of securing connection information in the PHP Cookbook (O'Reilly) by David Sklar and Adam Trachtenberg. They propose using 'SetEnv' in the Apache configuration and then accessing the values from within a script using $_SERVER.

Unfortunately using the 'SetEnv' solution exposes your connection information to all users of that virtual host. If they run phpinfo.php or display $_SERVER, I found that they will see the password from any file under the root of that virtual host.

To restrict exposure to a particular directory or specific file:

1. First put an 'Include' to the secret file in httpd.conf. For example:

Include "/web/private/secret.txt"

2. In the password file, use the 'SetEnvIf' directive to enable the Environment variables by directory only or within a specific file. For example:

I started getting "ORA-12514: TNS:listener does not currently know of service requested in connect descriptor" errors when I upgraded my database instance from 10.2 to 11.2. For some reason it would not resolve the oci_connect calls with the Easy Connect syntax (easy connect calls from sqlplus were fine). I was able to workaround the issue by passing a tns connect string:

For a quick and dirty ldap tnsnames server use tnsManager by Dave Berry. Oracle OID or Openldap can used, but are complicated to setup. tnsManager is a no brainer. The default port is 1575.

The order of values in NAMES.DIRECTORY_PATH from sqlnet.ora determines which look up 'adapter' is used first, in this case it is tnsnames.ora file and then ldap. I use ldap for general consumption and tnsnames.ora file to override ldap or entries that are not for general consumption.

If you have the full Oracle client you have tnsping. 'tnsping ORACLE_SID' will tell you what adapter you are using: 'Used LDAP adapter to resolve the alias'.

ISSUE:
For some reason PHP tries the HOSTNAME adapter first, and if the database name resolves in DNS, it will try connecting using the database name as the hostname with no SID or SERVICE_NAME defined. All other Oracle clients I have used will not try the HOSTNAME adapter unless it is listed in NAMES.DIRECTORY_PATH.
I have heard that LDAP look up does not work with older instantclients.

How to connect from PHP to an Oracle database using OID (Oracle Internet Directory):

OID is like a lookup index that contains connection strings for connecting to various databases. Without OID, a database connection string would be stored directly in the code settings and used by the PHP code to connect to a database. With OID, a lookup can be made to the OID LDAP to acquire the database connection string. Then the PHP code will use the acquired database connection string to connect to the database as before.

OID allows a DBA to manage/change which database server that an application uses without having to change any database settings in the PHP application itself or on the application server.

Here are the basic steps for PHP to connect to a database via OID:

- The DBA should provide you the connection information for the OID LDAP as well as the username/password for the database connection.
- Connect to the OID LDAP using the provided information
- Search for the appropriate LDAP record
- Get the connection string data from the record attribute, \&quot;orclnetdescstring\&quot;
- Close the LDAP connection
- Use the acquired connection string data to connect to the database as usual using the provided database username/password.

If you upgrades the OCI8, be sure to use the latest oracle instantclient version, otherwise you can receive an "ORA-24315: illegal attribute type" when trying to connect due to incompatibility with some versions.